问题

Have you realized the difficulty we have ____ the problem?
A:worked out
B:to work out
C:work out
D:working out
B:to work out
C:work out
D:working out
正确答案是:
同类题型
Did you take enough money with you? — Yes, but I spent ________ I had expected.
In my opinion, Jack, though relatively stubborn, was not too difficult ___.
I need my hat, my notebook and a pen. Can you _________ them to me?
I am still curious _____ what happened to her _____ that cold winter evening. [ ]